This is a U.S. original patent application which claims priority on Great Britain patent application No. 0123479.8 filed Sep. 29, 2001.
This invention relates to the field of photographic processing, in particular to the drying of processed media.
In conventional prior art-processors the processed media is passed through a large air chamber for drying. Heated air flows through the chamber but the air flow is not directed in any particular path. The media generally loops around within these large chambers until they are dry. The drying chambers generally cover an area in the region of 25 cm2.
The invention aims to provide a dryer which has a smaller footprint than those known in the prior art and which can be used in a free standing xe2x80x9ckioskxe2x80x9d type processing machine. The invention also aims to provide a dryer with minimal moving parts.
According to the present invention there is provided a dryer comprising a blower, means for dividing an airflow to flow into two chambers, one wall of each chamber being defined by an apertured plate member, the plate members defining a channel therebetween for the passage of a strip of material to be dried, the channel increasing in cross-sectional area along the length thereof such that air flowing along the channel is subject to a pressure drop causing the air to flow substantially in one direction along the channel.
The invention further provides a method of drying a strip of material wherein the material is transported through a channel of increasing cross-sectional area, air being fed into the channel via apertures in opposing walls of the channel and passing substantially in one direction along the channel due to a pressure drop created by the increasing cross-sectional area thereof, the material riding on a self-centering air cushion.
The invention allows for rapid drying of the photographic media. There is no physical contact by rollers or guides during the drying between the media and the dryer. There are therefore fewer moving parts than dryers known from the prior art. This leads to lower costs and less maintenance.
Only low back pressure is required for the airflow and this enables the use of cheaper commercially available hot air blowers. Due to the controlled airflow it is easier to feed the media into the entrance of the dryer.